Formation of Prothrombin Derivatives From Purified Prothrombin

Abstract

Two derivatives of purified prothrombin were obtained. Both are refractory to the action of Ca plus thromboplastin plus Ac-globulin. One forms when purified prothrombin is dissolved in 25% Na citrate soln. plus 3,4,4[image]-triaminodiphenyl sulfone. The other forms when 3-chloro-4,4[image]-diaminodiphenyl sulfone is used in conjunction with the 25% Na citrate soln. The latter derivative eventually becomes transformed into thrombin, and probably represents an intermediate in the process of thrombin formation. It is suggested as a possibility that this intermediate always forms when prothrombin becomes activated.